This series of Sampling Valves  are of the conventional screwed front piston type, but with special chevron PTFE seals which when closed by the operator guarantees a leak free valve. The valves are only made in 316 stainless steel and in 4 sizes from 10 mm to 25 mm pistons. A wide range of accessories are available to further improve the safety in sampling.  When the valve is fully closed the front of the piston is flush with the front of the valve when fitted to a vessel or pipeline. A version is available as a special to give a 30 mm extension of the piston in front of the valve.  The standard ex- stock valves have BSP threads but NPT can be offered to order as an alternative.